The Otto H. Kahn House is a mansion at 1 East 91st Street, at Fifth Avenue, in the Carnegie Hill section of the Upper East Side of Manhattan in New York City. The four-story mansion was designed by architects J. Armstrong Stenhouse and C. P. H. Gilbert in the neo-Italian Renaissance style. It was completed in 1918 as the town residence of the German-born financier and philanthropist Otto H. Kahn and his family. The Convent of the Sacred Heart, a private school, owns the Kahn House along with the adjacent James A. Burden House, which is internally connected. The mansion is a New York City designated landmark and, along with the Burden House, is listed on the National Register of Historic Places.

Carnegie Hill is a neighborhood within the Upper East Side, in the borough of Manhattan in New York City. Its boundaries are 86th Street on the south, Fifth Avenue on the west, with a northern boundary at 98th Street that continues just past Park Avenue and turns south to 96th Street and proceeds east up to, but not including, Third Avenue. The neighborhood is part of Manhattan Community District 8.